Unraveling Cotton Fiber Development Using Fiber Mutants in the Post‐Genomic Era

Abstract

Cotton (Gossypium spp.) fibers are unicellular trichomes that differentiate from ovule epidermal cells. Cotton fiber development is divided into four distinct yet overlapping stages: initiation, elongation, secondary cell wall (SCW) biosynthesis, and maturation. There are numerous naturally occurring and man‐made fiber mutants that display aberrant phenotypes ranging from fiberless to extremely short fiber, and to immature fiber. These mutants have provided cotton researchers an excellent model system to study fiber growth and development. During the past two decades, much advancement in the understanding of fiber development has been achieved through comparative analyses of fiber mutants and wild‐type cotton lines using a variety of technologies such as transcriptomic analysis and genetic mapping. The causative genes of five mutations related to fiber initiation, elongation, or SCW assembly have been identified. Lint and fuzz fiber initiations are regulated by MYBMIXTA‐like transcription factors along with many other genes. Cytoskeleton actins play a critical role in fiber elongation. Genes that are involved in biological processes such as transporting osmoticum or loosening cell walls are highly expressed during the elongation stage. Production of large amounts of cellulose at the SCW stage requires a sustainable supply of energy and carbohydrate precursors. Plant hormones affect fiber development. In this paper, we review progress in the elucidation of fiber development mechanisms based on analyzing fiber mutants and summarize genes and mechanisms that are critical to fiber development. We identify research gaps that should be future research priorities and provide a future perspective.

Genetic Identification and Transcriptome Analysis of Lintless and Fuzzless Traits in Gossypium arboreum L.

“…Understanding the fibre development will be crucial for breeding high lint yield and high-quality cotton varieties. Several genes have been identified and verified to be functional in fibre initiation in G. hirsutum and G. barbadense [31]. However, little is currently known about fibre and trichome initiation in G. arboreum.…”

“…There are several naturally occurring and mutagenesis-induced fuzzless accessions in different cotton species. Previous studies have identified multiple loci controlling the fuzzless trait in tetraploid cottons [22,[29][30][31]. Two of these have been mapped and investigated in detail.…”

Surface and Thermal Characterization of Cotton Fibers of Phenotypes Differing in Fiber Length

“…There are numerous naturally occurred and human-made fiber mutants that display various fiber phenotypes [7]. These include, among others, fiberless mutant lines MD17, SL1-7-1, and XZ142w [8,9]; seeds with only lint fibers and no fuzz fibers in the naked seed lines N 1 [10] and n 2 [11]; and seeds that are described as extremely short lint fibers in the Ligon lintless-1 (Li 1 ) [12], Ligon lintless-2 (Li 2 ) [13], Li x [14] and li y [4] mutant lines.…”

Characterization of cotton ARF factors and the role of GhARF2b in fiber development

“…The study of cotton fiber development regulation provides not only valuable knowledge to understanding plant cell growth and cell wall biosynthesis, but also candidate genes for cotton molecular breeding [4]. To date a number of genes that function in cotton fiber cells have been identified, including homeodomain transcription factor GaHOX1, GhHOX3 and GhHD1 [5][6][7], bHLH transcription factor GhPRE1 [8], KNOX transcription factor knl1 [9], the sterol carrier gene [10], MYB transcription factors GhMYB25, GhMYB25-like, GhMML3 and GhMML4 [11][12][13][14], NAC transcription factor fsn1 [15], transcription factor WLIM1a gene [16], sucrose synthase gene [17], cotton actin1 gene [18], cotton BURP domain protein GhRDL1 [19], ethylene pathway related genes [20], fasciclin-like arabinogalactan protein, Ghfla1 [21], and TCP transcription factor GhTCP4 [22] etc.…”